I finally finish installing KDE 4 on a Fedora, I used F7 for this, I am still trying to install it on CentOS, but in F7 it is installed.

check the threads on the forum, I am using the forum, to make it easier for you, to post your problems and interact if you are having problems installing or compiling KDE 4 on CentOS, Fedora, Debian or Ubuntu, I will later post the same how-to install KDE 4 on Debian and Ubuntu.

How to install KDE4 on Fedora

How to install KDE4 on CentOS